A. Bark present; leaves needle-like – Plant 1
A’. Bark absent; leaf with blade – go to B
B. Perianth absent, flowers in catkins – Plant 4
B’. Perianth present; flowers single or in a raceme – go to C
C. Flowers white; single pistil – Plant 2
C’. Flowers violet; many pistils – Plant 3
I didn’t think about including bark in the key, thanks for the idea.
Would another option be to start with the two choices of bark and no bark, and then move down to the leaf shapes? As well as B and B’ – to have the perianth absent or present, and then the next step under these choices, be the flower options? I get overcomplicated, and then I get too simple, so definitely could use some more practice.
Yes, that would definitely work. The nice thing about dichotomous keys is there is always more than one way to identify your specimens. I tend to provide two characters per couplet and try to be descriptive where possible (refrain from ‘bark present’ vs ‘bark absent’ – I realize I did this in my first couplet but tried to be descriptive in the second character for that first couplet).